John, The current of 23.4A is max current, and is used to calculate the heat release. Your report should also contain a "nominal" current, under normal operation (since all phones off hook at once is rare, to put is safely). It is understood in the industry that equipment produced now does not meet the requirement that exists in GR-63, which is actually 27.9 W/ft2/vert.ft for forced air cooled and 20.9 W/ft2/vert. ft for convection cooled. But in any case, to answer your question about the equipment being located all in one rack, what the RBOC will do is ask how many additional feet are required for the unit to meet the GR-63 objectives for heat release. By providing this information, in some cases the RBOC will allocate more space for that device, by leaving more room in the rack, for example. There is no allowance taken for POTS configs, and it is probably better that way for 2 reasons: 1. The RBOCs are very aware of what they are purchasing, and they will make concessions for certain equipment. 2. If there was a stipulation for POTS equipment, than they would have to make a stipulation for a multitude of equipment for various reasons, which would make this testing even more aggrivating than it already is!! I hope this helps somewhat, and let me know if you have any other questions, or need other clarification. Regards, Don Bennett Director of Telecom Compliance Garwood Laboratories 7829 Industry Ave. Pico Rivera, CA 90660 Ph: 562-949-2727 Fax: 562-949-8757 www.garwoodtestlabs.com ----- Original Message ----- From: John Loiselle <jloise...@integralaccess.com> To: <nebs@world.std.com> Sent: Monday, October 14, 2002 6:48 AM Subject: Equipment Area Heat Release Objective
> Hello, > I am requesting information to help me obtain a better understanding of the > requirements called out in GR-63, 4.1.4, R4-11, O4-12, O4-13, and Table 4-6. > I have a "shelf" equipment configuration with the following Assumptions > noted in the report: > > Rack depth (Rd) is 1 ft. > Rack width (Rw) is 2.17ft. > Maintenance aisle depth (Md) is 2.5 ft. > Wiring aisle depth (Wd) is 2 ft. > Height of equipment is 2ft. > Maximum operating voltage (V) is 48VDC. > Maximum operating current (A) is 23.4. > > My report states that I do not conform to O4-12. The calculated Heat > Dissipation was 80W/ft2/ft (2790W/m2/m). > > Since more than half the current draw is derived from POTS (all phones being > off hook at the same time), I am curious if the 23.4A is the correct number > to use for this calculation. It appears that the heat would not be > dissipated inside the enclosure but at the other end of the cable (phone?). > When I see various TDM enclosures, they are physically smaller and the port > density is greater. How are these enclosures allowed to fill a rack in one > bay? Is there allowances taken for POTS configurations? Thanks. Regards, > John Loiselle > Regulatory Compliance > Integral Access, Inc. > ph (978) 367 7585 > >
